Conventional ultra violet (UV) light sources provide very bright, broadband light which may be useful in a variety of commercial applications, such as UV water disinfection for municipalities and the like, or other applications where UV light is needed.
One typical conventional UV light source or lamp includes a bulb filled with a noble gas or a mixture of noble gases and trace amounts of a light emitting element, such as mercury. A radio frequency (RF) generator is coupled to a primary winding on a magnetic core which surrounds a portion of the bulb. The RF generator provides radio frequency power to the magnetic core wrapped around the lamp. This induces a high current Townsend-type avalanche in the lamp, in turn ionizing the gases in the bulb to form a plasma. The high current in the plasma excites the molecules of the light emitting element or elements, causing them to emit UV light.
One problem with conventional UV lamps is the magnetic coupling core surrounding the bulb, which blocks the UV light. Another problem with conventional UV lamps is that since more power is needed to create more UV light, the size of the transformer increases with the desired light output. As the size of the transformer increases, more light is blocked. This results in large, lossy light blocking magnetic cores. Such cores may require extensive cooling and may put a hard limit on the power transfer to plasma, the optical efficiency, and the radiant light flux. Thus, this is a significant scaling problem when large amounts of UV light is needed, such as for UV water disinfection, polymer curing, ink curing, or other similar applications which require a high brightness UV light source.